1. Field of the Invention
The invention is concerned with tubes made of a composite material and consisting of a fibrous reinforcement. More particularly, the invention is concerned with a process for the manufacture of said tubes.
2. Description of Related Art
Processes for the manufacture of tubes of composite material with a resin and a fibre reinforcement conventionally comprise the following steps:
a) manufacture of a mandrel of a suitable shape: cylindrical or conical, for example, for a mast or a fishing rod.
b) cutting out a sheet of material into widths, the shape and size of each width depending on the geometry of the tube and on the number of rolls which are to be made.
c) preimpregnation of the material with a resin constituting the matrix of the composite substance. After impregnation, the preimpregnated material, known thus as a "prepreg" is either stored or implemented for the next step.
d) fixing an edge of the width of the prepreg onto a generatrice of the mandrel: this operation is usually carried out by heat sealing using a steam iron. The edge of the prepreg is firstly positioned on a generatrice, and a steam iron is applied to it. Under the effects of the heat and also as a result of the pressure exerted, the prepreg which appeared dry and non-sticky initially, becomes sticky and adheres to the mandrel.
e) rolling around the mandrel using-a suitable system such as a laterally moving heating table.
f) the tube thus formed is enveloped by a case, plastic or cellophane film, intended to maintain the tube's cohesion during the subsequent step.
g) cross-linking of the composite material, removal of the mandrel and removal of the plastics case.
h) possible heat treatment.
A process of this kind is described in Japanese Application No. 54-155727.